Tic Disorders: Frequently Cooccurring Symptoms or Disorders

Frequently Cooccurring Symptoms or Disorders

Cooccurring problems can be more disabling than tics and are of-ten the reason people with tics come to clinical attention. Difficul-ties with mood, impulse control, obsessive–compulsive behaviors, anxiety, attention and learning problems, and conduct problems are common. In some patients, these problems reach diagnosable proportions, but in many others, they are less severe and do not fulfill diagnostic criteria. The most frequent cooccurring disorders are attention-deficit/hyperactivity disorder (ADHD; 50–60%) and obsessive–compulsive disorder (OCD; 30–70%). The exact rela-tionship of these problems to Tourette’s disorder is controversial.

Attention-deficit/Hyperactivity Disorder

Upward of 50% of clinically ascertained children and adolescents with Tourette’s disorder may be affected with problems of atten-tion, concentration, activity level, or impulse. In community-based epidemiological samples of subjects with Tourette’s dis-order, the estimated frequency of ADHD is lower (8–41%) than in clinic populations (Apter et al., 1993). In the epidemiological study with the lowest prevalence estimate of ADHD in Tourette’s disorder (8%), subjects were 16 to 17 years of age, and the assess-ment of ADHD focused on current affected status (point preva-lence), not lifetime diagnosis (Apter et al., 1993). Even though the point prevalence of ADHD was more than twice than that seen in the general population, factors such as the age of the sample and examination for current status probably led to an underestimate of ADHD in Tourette’s disorder.

Obsessive–Compulsive Symptoms

Obsessions and compulsions are stereotyped, persistent, and in-trusive thoughts and behaviors that are experienced as senseless. Because these thoughts and behaviors can be common in the gen-eral population, persons are considered “disordered” only when the obsessions or compulsions become severe, disabling, or time-consuming. Obsessions that are commonly seen in OCD include fears of contamination, fears of harm coming to oneself or others, scrupulosity, fear of losing control of one’s impulses, counting, fear of losing things, fear of being unable to remember, or expe-riencing images of terrible things happening. Compulsions com-monly seen in OCD include repeated or stereotyped washing and grooming rituals; repeated checking of locks, switches, or doors; and repetition of other senseless rituals.

Differences in clinical phenomenology have been noted in studies of obsessions and compulsions in patients with Tourette’s disorder compared with patients with OCD (without Tourette’s disorder). Patients with Tourette’s disorder have greater con-cern with physical symmetry, evenness, and exactness, which are often described as “just right” phenomena and concerns with impulse control. In contrast, patients with OCD have more frequent concerns regarding contamination and more cleaning and grooming rituals than do patients with Tourette’s disorder. Also, the absolute number of independent concerns appears to be greater in patients with Tourette’s disorder than in patients with OCD. Patients with OCD more often have a single concern around which their symptoms coalesce, such as contamination.

In contrast, patients with Tourette’s disorder may have multiple concerns, such as symmetry, violent or sexual images or urges, worries about losing control, or counting. Some investigators have argued that the obsessions and compulsions in Tourette’s disorders are more sensory–motor in character, whereas those in OCD are more cognitive and affective.